hello, for a 2-dim structured mesh (with multi-blocking) i have following Element types : NODE, LINE_2 and QUAD_4 How to export the mesh to CFX? I tried the options in OUTPUT but ... With ANSYS CFX it seems one should convert into unstructured? I DONT want this. Thank you

CFX cannot read 2D meshes. You need to extrude a 2D mesh for one element and put symmetry planes on top and bottom. This is explained in the documentation.

It is quite amazing that CFX does not support proper 2D simulations. While I realise it would be a re-write of the code this would have to be one the most requested features. I don't like the chances of it ever appearing - not until we get the software which supercedes CFX and Fluent and that's plenty of years off yet. We can but hope.

thank you , which 'ELEMENT' Glenn ? I have a pre-mesh with QUAD_4 elements. How can i extrude the blocks? I am now making surfaces for each block and then associating face:surface. How to proceed? greetings

Once you have the pre-mesh use the Mesh > Extrude function. Select all elements and extrude one layer your desired thickness. Then you'll need to re-assign the new quad faces to appropriate parts for boundary conditions.

Although we can write a 2D Finite Volume code, but the commercial code should cover the most general case.
for 2D modeling, I suggest Gambit, then import .msh file to CFX. If you are doing by means of ANSYS Mesh or ICEM, you should extrude your geometry as 1 element thickness (depending on your element size).